Fuse plug



Nmzzmw, m5@ 462 N.VM NUTT FUSE PLUG Filed Sept. 17. 3.926

mun

A A INI/ENlW/. Nawnmu WN,

y ATTORNEY Patented Nonu 2li?, i192?,

El will film .n i

FUSE PLUG.

application nlel September 1'?, 1926.

rlhe invention relates to an electrical thermal plug, and more especially to that clase ot electrical tuse plugs of the screw type, designed as an automatic cutout i'or electric circuits.

The primary object ot the invention is the provision or' a fuse plug, wherein the fusible element is confined within a closure, so that in event ot the melting oit the fuse there is no liability ot the sparks escaping or flames spreading causing tires or accidents, the plug being oi novel form, as it includes a mini mum number of parts, which are readily and easily assembled and when in this condition the said plug will be compact and constitute a unitary structure.

Another object o'l the invention is the provision of a plug ot this character, wherein the 'fusible element is conlined and held within a. chamber 'formed in an insulation shell or body in a novel manner, the latter being closed by a cap which is sealed upon the shell or body and has a peep opening so that the fusible element can be readily visible to ascertain whether or not it has become melted, when a short circuit occurs in the electrical circuit within which this plug is arranged, the fusible element being held fast within the shell or body in a unique manner and also the said shell or body and the cap are interloclred with each vother and sealed in a. novel manner.

A. further object ot the invention is the provision of a fuse plug` ot this character', wherein the insulating members are interloclred with each other and hermet-ically sealed to confine the fusible element, so that when the same becomes melted, there is no possibility of the escape of sparlrs or a flame, thereby preventing accidents and possibility of contlagration, the plug being ot the screw type, the screw apron being held upon the plug in a unique manner and all of the parts of such plug are assembled in a simplied way.

A still 'further object ot the invention is the provision ot a plug of this character, which is extremely simple in construction, possessing but :tew parts and these being` constructed, to enable the same to be assembled with dispatch and when in assembled relation to each other present a unitary struc ture, thoroughly reliable and etlicient in its purpose, strong, durable, and inespensive to manufacture.

Serial No. 136,134.

lll/Vith these and other objects in View, the invention consists in the features ot' construction, combination and arrangement of parts, as will be hereinafter more fully described in detail` illustrated in the accompanymg drawing, disclosing the preferred embodiment olI the invention, and pointed out in the claims hereunto appended.

ln Jche accompanying drawing Figure 1 is aside elevation of a fuse plug, constructed in accordance with the invention.

Figure 2 is a plan view looking toward the cap end of the plug.

Figure 3 is a side elevation, partly broken away, showing in detail certain adjunct parts and the assemblage thereof.

Figure 4 is a vertical longitudinal sec`v tional View through the plug.

Figure 5 is an inner tace plan View of the cap of the plug detached.

Figure 6 is a detailed plan View of the plug with the cap removed, showing the screw element and the fusible element assembled with relation to the body or shell of the plug, the cap being removed.

Similar reference characters indicate corresponding parts throughout the several views in the drawing.

Referring to the drawing in detail, A. designates generally the main body or shell of the fuse plug, B the screw 'errule and apron, C the removable cap or closure head and D the fusible element, the details of these being hereinafter more fully described.

The shell or body A of the plug is preferably made of insulating material, as for eX- ample porcelain and is oit' cylindrical cup shape to provide a fuse chamber 10, in which is located and conlined fusible element l), which is in the 'form of a strip of soft fusible metal, one end thereof being soldered or otherwise permanently secured at 11 to a hollow contact rivet 12, the same being passe-d centrally through the outer closed end ot the body or shell A and clinched thereto at itsperipheral edges as at 13. This fuse strip D is bent into substantially L- shape for a major portion of its length, while the other end is deformed to provide a stepped terminal 14 for a purpose presently described.

rlhe open end 15 ot the shell or body A is cut into from the outer peripheral edge at intervals to provide alternate series of PrD CII

lli)

notches 16 and radial ribs 17, respectively, as is clearly illustracd in Figure 6 oit the drawing.

The inner peripheral edge 18 of the open end o1I the shell body S is lorined with a slot 19 through which Yfreely passes the fusible eleinent D so that the stepped terminal 14 of the latter will be. seated in one ont the notches 16 and Vthe extremity thereotA lies against the external surface oi` said shell or body A as is clearly apparent in Figure f1 of the drawing.

The screw 'terrule l if` oreierably made from relatively thin shee` metal to provide for an annular apron or sleeve 2O concentrically arranged exteriorly ot the shell or body A and distorted to provide a screw thread, the inner edge ot the sleeve 2O being cut into to provide series of spaced, bend able tongues 21 Ywhich are turned inwardly to engage in the respective notches 16 the inner enc 15 of the shell r body A. These tongues 21 rest within the notches 1G as is clearly shown in Figure il o'f the drawing.

The cap C is preferably nia-de troni insulation material, for e1; tuple porcelain, and is of circular contour `ini-ving at its outer end a corrugated riin 22, while the inner end is in the :torni et a circular recess of a size to receive the ribs 1? on the inner open end 15 ot the body or shell A. Frein the wall 23 of this circular recess extend radially disposed lugs 211 which' are spaced apart and alternatewith notches 25 therebetween, these notches 25 being designed to receive the ribs 17 of the shell or body 1i. while the notches 16 in the latter are designed to receive the lugs 24 ot the cap C when the latter is placed upon the body or shell A into position as yshown in Figure L1 of the drawing. The cap C centrally thereo'l' is formed with an opening constituting a peep hole or window 2G which is covered with transparent panel 27 of disc forni, prefeial'lly inade from niica and is confined within the central circular recess in the cap and rests upon the open end 150i the body or shell A when the cap is in position upon the body or shell A. as is clearly shown in Figure i olf the drawing.

The outer end ot Vthe cap C is provided with a hexagonal shaped countersink 28, in axial alignment with,I the window or peep opening 26 and serves as an identification medium for the particulareharacterof screw plug-in the marketing oit the saine. The cap C and the body or shell A are joined togetherby an adhesive and interloeked by the coacting notches 1G and 23 and ribs and lugs 17 and 24v, respectively, on said parts, the adhesive beingl in the 'lorn'i of a cement or other adhesive substance 29 placed at the juncture between the point oi separation ot said parts.

Inthe assemblage et the fusible plug the errule B is placed upon the body A, with the tern'iinal 1li of the 'fusible ele-ment D con- Ylined within one oit the notches 16 of said shell or body il with one of the tongues 21, of the said iierrule B overlying` the terminal 111-. rlhercaiter the cap C is placed upon the open ond 15 o1 the shell or body A with the ribs li" engaged in the notches and the lugs 211- engaged in the notches 16, it being understood, ot course, that the transparent disc 27 is iithin the central recess in the inner end of said cap C and will rest upon the edge ot the open edge 15 of the body or shel'l A, this assemblage beingv clearly disclosed in lrEigure 4l ot the drawing. 'l`hereaiifter the cen'ient 2S) is applied to the joint between these separable parts, namely the shell or body A, terrule and cap C and when hard exe-l unites the parts and renders the'sanie a unitary structure.

'lhe Yfusible eleinent D can be readily visible through the transparent disc 27 and the kiblc plug assen'ibled in the inanner as hereinbe'liore described is screwed into an electric plug socket in the usual well known manner to close an electric circuit at the switch box or other point o'l an electrical layout or 'systern. When the fusible element D is melted by reason ot an overcharge or a short circuit in the electric 'layout or system, there is no pes ibility of the escape oit sparks or a iianie trein the chaniber 10.

Freni the foregoing it is thought that the construction and manner of use of the plug will be clearly understood, therefore a more extended explanation has been omitted.

llihat l claim is 1. A fuse plug, comprising a substantially cup-shaped body inade Yfrein insulating man torial 'torining a fuse chamber opening 'through one end of the body, a contact in the closed end ot said body, a strip like fusible element engaged at one end with the contact and extending through the chamber, said body being it'orined with spaced external notches cireuin'lferentially opening through the outer tace and open end of said body to present radial ribs at said end, a screw lierrule removably embracing the body and l'iaving inturned tongues resting in the notches, the free end oli' the fusible element being clinched between the lerrule and body and resting in one notch, and aninsulating cap ot substantially circular contour having a recess receiving the open end of ythe body, the wall oll the recess being` termed with radial. lugs eon'nnon to and engaging the notches.

2. fuse plug, comprising a substantially cup-shaped body inade troni insulating material lorining a fuse chamber opening tlnfough one end of the body, a contact in the closed end ol' said body, a strip like fusible eleinent engaged at one end with thecontact and extending through the chamber, said body being termed with spaced external notches circumferentially opening through the outer face and open end of said body to present radial ribs at said end, a screw ferrule removably embracing the body and having inturned tongues resting in the notches, the free end of the fusible element being` clinched between the iierrule and body and resting in one notch, an insulating cap of substantially circular contour having a recess receiving the open end of the body, the wall ot' the recess being formed with radial lugs common to and engaging the notches, and an adhesive substance joining the cap and body.

3. A fuse plug, comprising a substantially cup-shaped body made from insulating material forming a fuse chamber opening through one end of the body, a contact in the closed end of said body, a strip like fusible element engaged at one end with the contact and extending through the chamber, said body being' vformed with spaced eXte-rna'l notches circumferentially opening through the outer face and open end of said body to present radial ribs at said end, a screw ferrule removably embracing the body and haV- ing int-urned tongues resting in the notches, the free end of the fusible element being clinched between the 'errule and body and resting in one notch, an insulating` cap of 'substantially circular contour having a recess receiving the open end of the body, the wall of the recess being formed with radial lugs common to and engagingl the notches, and an adhesive substance joining the cap and body, the inner end portion of the cap presenting at the outer portion thereotl an unbroken con tinuation of the outer surface of the body.

ln testimony whereof, I aliix my signature hereto.

NORMAN W. NUTT. 

